High-efficiency coal water slurry additive and preparation method thereof

Abstract

The application relates to the field of coal water slurry, and more particularly to a high-efficiency coal water slurry additive and a preparation method thereof. The high-efficiency coal water slurry additive is prepared from raw materials including an auxiliary dispersant 20-40% by mass, a stabilizer 10-20% by mass, an interface agent 5-10% by mass, a combustion-supporting agent 1-5% by mass and a modified base agent to make up the rest. The coal water slurry additive prepared through the application has excellent dispersing effect, good stability and other advantages, can simultaneously meet the requirements of the stability, fluidity and combustion performance of the coal water slurry system, and greatly improves the storage and use quality of the coal water slurry system, and has very wide application potential.

Description

Technical Field

[0001] This application relates to the field of coal-water slurry, and more specifically mentions a high-efficiency coal-water slurry additive and its preparation method. Background Technology

[0002] Coal-water slurry, as a clean and efficient coal-based fuel, has been widely used in industrial boilers and power plant boilers due to its high combustion efficiency and low pollution emissions. Composed of pulverized coal, water, and a small amount of additives, coal-water slurry is a pumpable, storable, and combustible fluid fuel. It not only improves the utilization efficiency of coal but also reduces pollutant emissions generated during coal combustion, making it of great significance for environmental protection.

[0003] However, the performance of coal-water slurry, such as its stability, fluidity, and combustion performance, is affected by a variety of factors. Among these, the selection and performance of additives are crucial. Ideal additives can not only enhance the dispersibility and fluidity of coal-water slurry, but also improve its stability, ensuring that it is not prone to stratification or sedimentation during transportation and storage, and promote complete combustion during combustion, further reducing pollutant emissions.

[0004] Traditional coal-water slurry additives often use single components, such as lignin sulfonates and naphthalene-based dispersants. While these additives can improve certain properties of coal-water slurry to some extent, they generally have some problems, such as: limited dispersion effect, as single-component additives often cannot simultaneously meet the requirements of enhanced dispersibility, stability, and optimized combustion performance; and poor stability, as coal-water slurry prepared using traditional additives is prone to stratification after long-term storage due to the lack of comprehensive performance, reducing its utilization efficiency. Summary of the Invention

[0005] Therefore, in order to effectively solve the above-mentioned existing problems, this application provides a high-efficiency coal-water slurry additive and its preparation method. The coal-water slurry additive finally obtained by this application not only has the advantages of excellent dispersion effect and good stability, but also can simultaneously meet the requirements of stability, fluidity and combustion performance of coal-water slurry system, thereby achieving a significant improvement in the storage and use quality of coal-water slurry system, and has a very wide range of application potential.

[0006] The high-efficiency coal-water slurry additive, by mass percentage, comprises: 20-40% auxiliary dispersant, 10-20% stabilizer, 5-10% interface agent, 1-5% combustion improver, and the remainder is modified matrix agent.

[0007] In a preferred embodiment, the mass ratio of the modified matrix agent, auxiliary dispersant and stabilizer is (35-45):(25-35):(12-18).

[0008] In a preferred embodiment, the mass ratio of the modified matrix agent, the auxiliary dispersant and the stabilizer is (40-45):(28-32):(13-15).

[0009] In a preferred embodiment, the auxiliary dispersant is an acrylic acid-acrylamide copolymer.

[0010] In a preferred embodiment, the acrylic-acrylamide copolymer is an acrylic-2-acrylamide-2-methylpropanesulfonic acid copolymer.

[0011] In a preferred embodiment, the stabilizer is at least one selected from sodium chloride, calcium chloride, sodium sulfate, and calcium sulfate.

[0012] In a preferred embodiment, the stabilizer is a combination of sodium chloride and calcium chloride or sodium sulfate.

[0013] In a preferred embodiment, the mass ratio of sodium chloride to calcium chloride / sodium sulfate is (3-4):(0.8-1.4).

[0014] In a preferred embodiment, the mass ratio of sodium chloride to calcium chloride / sodium sulfate is (3-3.5):(1-1.2).

[0015] In a preferred embodiment, the interface agent is a composition of sodium dodecylbenzenesulfonate and cetearyl alcohol polyoxyethylene ether.

[0016] In a preferred embodiment, the mass ratio of sodium dodecylbenzenesulfonate to cetearyl alcohol polyoxyethylene ether is (6-8):(1-1.5).

[0017] In a preferred embodiment, the mass ratio of sodium dodecylbenzenesulfonate to cetearyl alcohol polyoxyethylene ether is (6.5-7):(1.2-1.4).

[0018] In a preferred embodiment, the combustion aid is at least one of potassium nitrate, sodium nitrate, potassium permanganate, barium nitrate, and hydrogen peroxide.

[0019] In a preferred embodiment, the combustion aid is at least one of potassium nitrate, sodium nitrate, and potassium permanganate.

[0020] In a preferred embodiment, the combustion aid is potassium nitrate.

[0021] In a preferred embodiment, the modifying matrix agent is a modified lignin sulfonate.

[0022] As a preferred embodiment, the preparation method of the modified lignin sulfonate specifically includes the following steps: S1: pulverize alkali lignin, add hydrochloric acid solution and stir to remove residual lignin sulfonate and ash, centrifuge and wash with water until neutral, then mix with ethanol, ultrasonically disperse and vacuum dry to obtain activated lignin; S2: add activated lignin, aminosulfonic acid and EDTA to a high-pressure reactor, then add a mixed solvent of ethanol and water, heat and keep the reaction at the specified temperature, then add allyl glycidyl ether, glycidyl methacrylate and ammonium persulfate, heat and keep the reaction at the specified temperature; S3: after the reaction is completed, cool the reaction system, slowly add acetone, let stand and separate the layers, centrifuge and collect the precipitate, then wash with a mixed solvent of ethanol and water and spray dry at high temperature to obtain the final product.

[0023] As a preferred embodiment, the preparation method of the modified lignin sulfonate specifically includes the following steps: S1: pulverize alkali lignin to 120-200 mesh, stir with 5-8% hydrochloric acid solution at 60-65℃ for 2-3 hours to remove residual lignin sulfonate and ash, centrifuge, wash with water until neutral, and then mix with ethanol at a mass ratio of 1:(3-4), ultrasonically disperse, and vacuum dry to obtain activated lignin; S2: add activated lignin, aminosulfonic acid, and EDTA to a high-pressure reactor, then add a mixed solvent of ethanol and water, and purge with nitrogen three times until the oxygen content is <5%. 0 ppm, heat to 80-85℃ and add dilute sulfuric acid dropwise to maintain pH at 2.5-3.0, keep the reaction at this temperature for 2-3 hours, add allyl glycidyl ether and glycidyl methacrylate, and add ammonium persulfate twice at 30-40 min intervals, heat to 90-95℃ and react for 4-5 hours; S3: After the reaction is complete, cool the reaction system to 35-40℃, slowly add 3-4 times the volume of acetone, let it stand to separate into layers, centrifuge to collect the precipitate, then wash it 2-3 times with a mixed solvent of ethanol and water to remove unreacted monomers and homopolymers, and spray dry at 150-160℃ to obtain the final product.

[0024] In a preferred embodiment, the mass ratio of the activated lignin, aminosulfonic acid and EDTA is (10-12):(4-4.4):(0.05-0.1).

[0025] In a preferred embodiment, the mass ratio of the activated lignin, allyl glycidyl ether, and glycidyl methacrylate is (10-12):(1.8-2.5):(1-1.5).

[0026] In a preferred embodiment, the volume ratio of ethanol to water in the ethanol-water mixed solvent is (3-4):1.

[0027] The addition of modified lignin sulfonate can effectively improve the overall performance of coal-water slurry additives. The linear polyether side chains introduced by the modified lignin sulfonate can provide long-chain steric hindrance to inhibit coal particle agglomeration, and the ester group (-COOR) can bind to the hydrophobic region of the coal surface to enhance the adsorption strength. The ester group can also partially decompose at high temperature to generate free radicals to promote micro-explosion of coal powder and increase the specific surface area of ​​the combustion reaction. On the other hand, the internal ether bond and epoxy group cross-linking form a three-dimensional network, which inhibits high-temperature chain segment movement and prevents thermal decomposition of the additive. Through aminosulfonic acid modification, the degree of sulfonation is increased, which enhances the electrostatic repulsion between coal particles. In summary, the addition of the above-mentioned modified lignin sulfonate can take into account both dispersion-stabilization and combustion-promoting effects, and significantly improve the overall performance of the additive.

[0028] The preparation method of high-efficiency coal-water slurry additive includes the following steps: S1: Mix the auxiliary dispersant, stabilizer, interface agent, combustion aid and modified matrix agent in a high-speed disperser in proportion and stir at 5000-6000 rpm for 20-30 min; S2: Transfer to a reaction vessel, heat to 70-80℃ and keep at that temperature for 1-2 h; S3: After the heat preservation is completed, cool naturally to room temperature, freeze-dry the product, grind it into powder, and pass it through a 100-200 mesh sieve to obtain the additive.

[0029] The beneficial effects of this application are:

[0030] 1. The high-efficiency coal-water slurry additive provided in this application not only has the advantages of excellent dispersion effect and good stability, but also can simultaneously meet the requirements of stability, fluidity and combustion performance of coal-water slurry system, thereby achieving a significant improvement in the storage and use quality of coal-water slurry system, and has a very wide range of application potential.

[0031] 2. The high-efficiency coal-water slurry additive provided in this application uses a mixed system of modified lignin sulfonate and auxiliary dispersant, which can effectively disperse coal powder particles, prevent particle agglomeration, improve the stability of coal-water slurry, and effectively prevent coal-water slurry stratification and sedimentation through a stable internal system, thereby improving the storage stability of coal-water slurry. Furthermore, through the combined action of the internal system, it ultimately helps to improve the fluidity and combustion performance of coal-water slurry.

[0032] 3. The high-efficiency coal-water slurry additive provided in this application, through the addition of modified lignin sulfonate, introduces linear polyether side chains that provide long-chain steric hindrance to inhibit coal particle agglomeration. Furthermore, the ester groups (-COOR) bind to the hydrophobic regions on the coal surface, enhancing adsorption strength. The ester groups can also partially decompose at high temperatures to generate free radicals, promoting micro-explosion of coal powder and increasing the specific surface area for combustion reactions. On the other hand, the internal ether bonds and epoxy groups crosslink to form a three-dimensional network, inhibiting high-temperature chain segment movement and preventing thermal decomposition of the additive. Through aminosulfonic acid modification, the increased sulfonation degree enhances the electrostatic repulsion between coal particles. In summary, the addition of the aforementioned modified lignin sulfonate can achieve both dispersion-stabilization and combustion-supporting effects, significantly improving the overall performance of the additive. Detailed Implementation

[0033] The specific implementation examples will be used to more intuitively demonstrate and explain the content of the invention in this application.

[0034] Example 1

[0035] The high-efficiency coal-water slurry additive, by weight percentage, comprises: 30% auxiliary dispersant, 15% stabilizer, 8% interface agent, 2% combustion aid, and 45% modified matrix agent.

[0036] The auxiliary dispersant was acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, which was purchased as an industrial-grade product from Shanghai Hongzhuang Chemical Technology Co., Ltd., China.

[0037] The stabilizer is a combination of sodium chloride and calcium chloride in a mass ratio of 3.5:1.

[0038] The interface agent is a composition of sodium dodecylbenzenesulfonate and cetearyl alcohol polyoxyethylene ether in a mass ratio of 6.8:1.2; the cetearyl alcohol polyoxyethylene ether was purchased from O-50 product sold by Haian Petrochemical Plant in Jiangsu Province, China.

[0039] The combustion improver is potassium nitrate.

[0040] The modified matrix agent is modified lignin sulfonate. The preparation method, by mass, specifically includes the following steps: S1: 11.5 parts of alkali lignin are pulverized to 150 mesh, treated with 90 parts of 5% hydrochloric acid solution at 60℃ for 2 hours to remove residual lignin sulfonate and ash. After centrifugation, the mixture is washed with water until neutral, and then mixed with ethanol at a mass ratio of 1:3. After ultrasonic dispersion, the mixture is vacuum dried to obtain activated lignin; S2: 10.2 parts of activated lignin, 4.2 parts of aminosulfonic acid, and 0.08 parts of EDTA are added to a high-pressure reactor, followed by the addition of 80 parts of a mixed solvent of ethanol and water (ethanol to water volume ratio of 4). :1) Purge nitrogen three times until the oxygen content is <50ppm, heat to 85℃ and add 10% dilute sulfuric acid dropwise to maintain pH at 2.8, keep the reaction at this temperature for 2h, add 2.3 parts allyl glycidyl ether and 1.4 parts glycidyl methacrylate, and add 0.08 parts ammonium persulfate twice at 30min intervals, heat to 90℃ and react for 4h; S3: After the reaction is complete, cool the reaction system to 40℃, slowly add 3 times the volume of acetone, let it stand to separate into layers, centrifuge to collect the precipitate, then wash it three times with a mixed solvent of ethanol and water to remove unreacted monomers and homopolymers, and spray dry at 160℃ to obtain the final product.

[0041] The preparation method of high-efficiency coal-water slurry additive includes the following steps: S1: Mix the auxiliary dispersant, stabilizer, interface agent, combustion aid and modified matrix agent in a high-speed disperser in proportion and stir at 5000 rpm for 25 min; S2: Transfer to a reaction vessel and heat to 75℃ and keep at that temperature for 1.5 h; S3: After the heat preservation is completed, allow it to cool naturally to room temperature, freeze-dry the product, grind it into powder, and pass it through a 100-mesh sieve to obtain the final product.

[0042] Example 2

[0043] The only difference between this embodiment and Example 1 is as follows: the high-efficiency coal-water slurry additive, by mass percentage, comprises: 35% auxiliary dispersant, 12% stabilizer, 10% interface agent, 3% combustion aid, and 40% modified matrix agent.

[0044] Example 3

[0045] The only difference between this embodiment and Example 1 is as follows: the high-efficiency coal-water slurry additive, by mass percentage, comprises: 27% auxiliary dispersant, 18% stabilizer, 10% interface agent, 5% combustion aid, and 40% modified matrix agent.

[0046] Comparative Example 1

[0047] The only difference between this comparative example and Example 1 is as follows: the coal-water slurry additive, by mass percentage, comprises: 30% naphthalene dispersant, 20% sodium chloride, and 50% sodium lignosulfonate.

[0048] The naphthalene-based dispersant was purchased from Shandong Wanshan Group Co., Ltd., China, and was classified as FDN-C premium grade product.

[0049] Comparative Example 2

[0050] The only difference between this comparative example and Example 1 is as follows: the coal-water slurry additive, by mass percentage, comprises: 50% polycarboxylate dispersant, 30% sodium chloride, and 20% sodium lignosulfonate.

[0051] The polycarboxylate dispersant was purchased from Shanghai Hengchuang Chemical Co., Ltd., China, and was product model PC-1055.

[0052] Comparative Example 3

[0053] The only difference between this comparative example and Example 1 is that the interface agent is a composition of sodium dodecylbenzenesulfonate and cetearyl alcohol polyoxyethylene ether in a mass ratio of 9.8:0.2.

[0054] Comparative Example 4

[0055] The only difference between this comparative example and Example 1 is that the auxiliary dispersant is sodium polycarboxylate sold by Nanjing Chuhai New Materials Technology Co., Ltd.

[0056] Comparative Example 5

[0057] The only difference between this comparative example and Example 1 is the following: the modified matrix agent is modified lignin sulfonate. The preparation method, by mass, specifically includes the following steps: S1: 11.5 parts of alkali lignin are pulverized to 150 mesh, treated with 90 parts of 5% hydrochloric acid solution at 60°C for 2 hours to remove residual lignin sulfonate and ash, centrifuged, washed with water until neutral, and then mixed with ethanol at a mass ratio of 1:3. After ultrasonic dispersion, vacuum drying is performed to obtain activated lignin; S2: 20.5 parts of activated lignin, 3.5 parts of aminosulfonic acid, and 0.08 parts of EDTA are added to a high-pressure reactor, followed by the addition of 80 parts of a mixed solvent of ethanol and water (ethanol...). The volume ratio of alcohol to water is 4:1. Nitrogen gas is purged three times until the oxygen content is <50ppm. The temperature is raised to 85℃ and 10% dilute sulfuric acid is added dropwise to maintain the pH at 2.8. The reaction is maintained at this temperature for 2 hours. 1.2 parts of allyl glycidyl ether and 3.5 parts of glycidyl methacrylate are added, and 0.08 parts of ammonium persulfate are added twice at 30-minute intervals. The temperature is raised to 90℃ and the reaction is carried out for 4 hours. S3: After the reaction is completed, the reaction system is cooled to 40℃. Three times the volume of acetone is slowly added. After standing and separating the layers, the precipitate is collected by centrifugation. Then, it is washed three times with a mixed solvent of ethanol and water to remove unreacted monomers and homopolymers. The precipitate is then spray-dried at 160℃ to obtain the final product.

[0058] Comparative Example 6

[0059] The only difference between this comparative example and Example 1 is the following: the modified matrix agent is modified lignin sulfonate. The preparation method, by mass, specifically includes the following steps: S1: 11.5 parts of alkali lignin are pulverized to 150 mesh, treated with 90 parts of 5% hydrochloric acid solution at 60°C for 2 hours to remove residual lignin sulfonate and ash. After centrifugation, the mixture is washed with water until neutral, and then mixed with ethanol at a mass ratio of 1:3. After ultrasonic dispersion, the mixture is vacuum dried to obtain activated lignin; S2: 18.5 parts of activated lignin, 4.1 parts of aminosulfonic acid, and 0.06 parts of EDTA are added to a high-pressure reactor, followed by the addition of 80 parts of a mixed solvent of ethanol and water (ethanol...). The volume ratio of alcohol to water is 4:1. Nitrogen gas is purged three times until the oxygen content is <50ppm. The temperature is raised to 85℃ and 10% dilute sulfuric acid is added dropwise to maintain the pH at 2.8. The reaction is maintained at this temperature for 2 hours. 5.5 parts of allyl glycidyl ether and 0.3 parts of glycidyl methacrylate are added, and 0.08 parts of ammonium persulfate are added twice at 30-minute intervals. The temperature is raised to 90℃ and the reaction is carried out for 4 hours. S3: After the reaction is completed, the reaction system is cooled to 40℃. Three times the volume of acetone is slowly added. After standing and separating the layers, the precipitate is collected by centrifugation. Then, it is washed three times with a mixed solvent of ethanol and water to remove unreacted monomers and homopolymers. The precipitate is then spray-dried at 160℃ to obtain the final product.

[0060] Performance Evaluation

[0061] This performance evaluation utilizes the company's own instruments and equipment, employing wet coal milling to simulate the on-site equipment and conduct a slurry evaluation. The wet slurry preparation experiment procedure is as follows:

[0062] (1) Use a fully sealed hammer crusher to crush the raw coal provided on site;

[0063] (2) The crushed raw coal is subjected to total moisture determination according to national standards and is ready for use;

[0064] (3) Configure the grinding media ratio according to the conventional particle size distribution of coal-water slurry;

[0065] (4) The target concentration was set at 62.5 wt% coal, 0.2 wt% of the additives prepared in the examples and comparative examples, and water to make up the balance. In this slurry preparation, 300g of coal slurry was used to make a slurry test. Coal, additives and water were accurately weighed according to the preparation requirements to prepare coal slurry.

[0066] (5) Set the coal grinding time according to the grindability index and particle size distribution. Coal-water slurry is obtained after the mill runs out.

[0067] (6) The prepared coal slurry was subjected to tests of apparent viscosity, concentration and fluidity, and then allowed to stand for 24 hours to determine its stability.

[0068] The coal-water slurry additives prepared in the examples and comparative examples were added to coal-water slurry, and the concentration, viscosity, stability, and flowability properties of the coal-water slurry were tested.

[0069] (1) Coal slurry concentration

[0070] The coal slurry concentration was determined using the oven drying method. The oven was set and heated to 105℃ (±2℃). A 3g ± 0.2g (accurate to 0.001g) coal slurry sample was weighed into a pre-dried, constant-weight weighing bottle. The heating time was 1 hour. After cooling to room temperature, the sample was weighed again. A check drying time of 30 minutes was performed until the mass remained constant or the slurry regained its original weight. The coal slurry concentration was calculated using the formula. The reference standard is GB / T 18856.2-2008.

[0071] (2) Coal slurry viscosity

[0072] The viscosity of coal slurry was measured using an NXS-4C water-coal slurry viscometer, with the automatic mode used. The reference standard is GB / T 18856.4-2008.

[0073] (3) Coal slurry fluidity

[0074] Using visual inspection, coal slurry was classified into three grades: A (continuous flow), B (intermittent flow), and C (almost no flow or no flow). Grade A is a thin fluid with continuous, smooth, and uninterrupted flow; Grade B is a thick fluid with relatively continuous flow but a rough surface; Grade C requires external force to flow well or is a muddy consistency that does not form a slurry and cannot flow. A "+" indicates better flowability in a given grade; a "-" indicates poorer flowability in a given grade.

[0075] (4) Coal slurry stability

[0076] Pour the coal slurry into a 100mL graduated cylinder, let it stand for 24 hours, and then read the scale value to determine the water separation rate. Perform a drop rod test using a glass rod to observe the sedimentation of the coal slurry, thus assessing its stability. The reference standard is GB / T18856.5—2008. Alternatively, after sealing and standing the coal-water slurry sample for 24 hours, observe the stability using the rod insertion method. The stability of the coal-water slurry is determined into four levels, as detailed below:

[0077] Grade A - Best stability, uniform slurry distribution, no water separation, no sedimentation, and the slurry remains as fluid as before after stirring;

[0078] Grade B - Good stability, no precipitation or a small amount of soft precipitation, with very little water separation and slight uneven distribution of slurry density;

[0079] Grade C - Poor stability, water separation, uneven slurry density distribution, and severe sedimentation, but can be regenerated into a uniform slurry after stirring.

[0080] Grade D - the least stable, with significantly uneven slurry density distribution, excessive water separation, hard sediment, and non-renewable.

[0081] Table 1 Performance Evaluation Table

[0082]

[0083] Based on the final performance test results of the examples and comparative examples, the slurry-forming performance of comparative examples 1-6 was worse than that of the examples. However, the examples, due to the adoption of a better technical solution, effectively dispersed coal powder particles through the combined action of modified lignin sulfonate and auxiliary dispersant, preventing particle agglomeration and improving the stability of coal-water slurry. Furthermore, the stable internal system effectively prevented the coal-water slurry from stratifying and settling, improving the storage stability of the coal-water slurry. Finally, the combined action of the internal system helped to improve the fluidity and combustion performance of the coal-water slurry.

Claims

1. A coal-water slurry additive, characterized in that: By mass percentage, the raw materials include: 20-40% auxiliary dispersant, 10-20% stabilizer, 5-10% interface agent, 1-5% combustion improver, and the remainder is modified matrix agent; The auxiliary dispersant is an acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer; The interface agent is a composition of sodium dodecylbenzenesulfonate and cetearyl alcohol polyoxyethylene ether in a mass ratio of (6~8):(1~1.5). The modified matrix agent is a modified lignin sulfonate, and the preparation method specifically includes the following steps: S1: pulverize alkali lignin to 120-200 mesh, stir with 5-8% hydrochloric acid solution at 60-65℃ for 2-3 hours to remove residual lignin sulfonate and ash, centrifuge, wash with water until neutral, and then mix with ethanol at a mass ratio of 1:(3-4), ultrasonically disperse, and vacuum dry to obtain activated lignin; S2: add activated lignin, aminosulfonic acid, and EDTA to a high-pressure reactor, then add a mixed solvent of ethanol and water, and purge with nitrogen three times until the oxygen content is <50%. ppm, heat to 80~85℃ and add dilute sulfuric acid dropwise to maintain pH at 2.5~3.0, keep the reaction at this temperature for 2~3h, add allyl glycidyl ether and glycidyl methacrylate, and add ammonium persulfate twice at 30~40min intervals, heat to 90~95℃ and react for 4~5h; S3: After the reaction is complete, cool the reaction system to 35~40℃, slowly add 3~4 times the volume of acetone, let stand for layering, centrifuge to collect the precipitate, then wash with a mixed solvent of ethanol and water 2~3 times to remove unreacted monomers and homopolymers, and spray dry at 150~160℃ to obtain the product; The mass ratio of the activated lignin, aminosulfonic acid, and EDTA is (10~12):(4~4.4):(0.05~0.1). The mass ratio of the activated lignin, allyl glycidyl ether, and glycidyl methacrylate is (10~12):(1.8~2.5):(1~1.5). The stabilizer is a composition of sodium chloride and calcium chloride or sodium sulfate in a mass ratio of (3~4):(0.8~1.4).

2. The coal-water slurry additive according to claim 1, characterized in that: The mass ratio of the modified matrix agent, auxiliary dispersant and stabilizer is (35~45):(25~35):(12~18).

3. The coal-water slurry additive according to claim 2, characterized in that: The combustion aid is at least one of potassium nitrate, sodium nitrate, potassium permanganate, barium nitrate, and hydrogen peroxide.

4. A method for preparing a coal-water slurry additive according to any one of claims 1 to 3, characterized in that: Specifically, the following steps are included: S1: Mix the auxiliary dispersant, stabilizer, interface agent, combustion aid and modified matrix agent in a high-speed disperser in proportion and stir at 5000~6000 rpm for 20~30 min; S2: Transfer to a reaction vessel, heat to 70~80℃ and keep warm for 1~2 h; S3: After the heat preservation is completed, cool naturally to room temperature, freeze dry the product, grind it into powder, and pass it through a 100~200 mesh sieve to obtain the product.

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